1. Field of the Invention
The present invention relates to connectors designed to double lock a terminal to a housing by use of a front holder.
2. Description of the Related Art
Connectors of this type are known from Japanese Patent Application Lad-open Publication Nos. Hei. 9-106847 ad 2004-241155.
FIGS. 1 and 2 show a connector of this type and each figure shows one connector (male connector) 101 of a pair of connectors fitted to each other. A housing 101A of this connector 101 includes: a housing main body 110 including a cylindrical section 111 for accommodating terminals 130, and a hood section 112 arranged around the outer circumference of the cylindrical section 111; and a front holder 120 to be fitted into the front side of the outer circumferential portion of the cylindrical section 111 from the front.
Terminal accommodating chambers 113 are formed inside the cylindrical section 111. A bendable lance 114 is provided to a part of the circumferential wall of each of the terminal accommodating chambers 113. Thus, the lance 114 locks a corresponding one of the terminals (female terminals) 130 which has been inserted into a corresponding one of the terminal accommodating chambers 113 from the rear of the housing main body 110 in order that the terminal can be stopped from coming out of the terminal accommodating chamber 113.
A bend allowing space 115 for allowing the bendable lance 114 to bend in response to the insertion of the terminal 130 is secured outside the bendable lance 114.
The front holder 120 is provided in a way that the front holder 120 is capable of being inserted into the housing main body 110 from a temporary locking position closer to the front (a position shown in FIG. 1) to a permanent locking position away from the front (a position shown in FIG. 2). Temporary locking means and permanent locking means (not illustrated) are configured respectively to temporarily lock the font holder 120 in the temporary looking position and to permanently lock the front holder 120 in the permanent locking position. These two means are provided between the housing main body 110 into which the front holder 120 is capable of being inserted and the front holder 120.
While the front holder 120 is in the temporary locking position, the bendable lances 114 are allowed to bend in the respective bend allowing spaces 115. Thus, the bendable lances 114 are capable of looking the respective terminals 130 which have been inserted into the housing main body 110 from the rear, and of hence preventing the respective terminals 130 from coming out of the housing main body 110.
As shown in FIG. 2, the front holder 120 is provided with lance pressing parts 121. When the front holder 120 is moved from the temporary locking position to the permanent locking position with the terminals 130 locked by their respective bendable lances 114, the corresponding lance pressing parts 121 enter their respective bend allowing spaces 115, and press the respective bendable lances 114 toward the terminals 130, thus prohibiting the bendable lances 114 from bending. As a result the terminals are double locked.
A rear end wall 122 of the font holder 120 which is located at the rear end in a direction in which the front holder 120 is inserted into the housing main body 110 is provided with terminal inserting holes 123 into which corresponding terminals (male terminals) of the connector pared with the connector 101 are inserted.
In a case when one is going to assemble the connector 101 with the housing main body 110, as shown in FIG. 1, first of all, the fits the front holder 120 to the front end portion of the cylindrical section 111 of the housing main body 110, and locks the front holder 120 to the housing main body 110 by use of the temporary locking means. While the front holder 120 is in this condition, the front holder 120 is prevented from being inserted into the housing main body 110 any more, and is held in the temporary locking position.
Subsequently, he insets terminals 130, to which corresponding cables are connected, into the respective terminal accommodating chambers 113 in the cylindrical section 111. At this time, the this 130 are temporarily looked by the corresponding bendable lances 114 in the cylindrical section 111 from the rear of the housing main body 110. In this state, the front holder 120 is inserted to the permanent locking position from the temporary looking position as shown in FIG. 2. As a consequent the front holder 120 is permanently locked to the housing main body 110 by the permanent locking means. At this time, the lance pressing parts 121 of the front holder 120 enter the respective bend allowing spaces 115 for the corresponding bendable lances 114. This checks the bendable lances 114 from deforming due to their respective bends. Thereby, the terminals 130 are double locked.
It should be noted that the connector 101 as shown in FIG. 1 is often handled in an assembled condition where the front holder 120 is temporarily locked to the housing main body 110. While the front holder 120 is in this temporary locking condition, the front holder 120 juts out from the front end 110a of the housing main body 110. For this reason, for example, when the front holder 120 hits another article or falls during its shipment or the like before the terminals are not attached thereto, the front holder 120 is inadvertently inserted for the temporary locking position to the permanent locking position in some cases. Once the front holder 120 is inserted up to the permanent locking position (the position shown in FIG. 2), work for inserting, the terminals 130 thereto can not be performed. For this reason, the front holder 120 has to be returned to the temporary locking position through releasing the front holder 120 from the permanent lock by taking some measures. This work is extremely troublesome.
With this taken into consideration, the following measures have been examined.
One measure is to forwardly extend out the front end of the hood section from the housing main body and thereby cover the front holder with the extended hood section (see Japanese Patent Application Lad-open Publication No. 2004-241155). The extension of the hood section bring about a problem that the connector is accordingly construed in a larger scale. In addition, in a case where the hood section is intended to prevent to front holder from being inserted into the housing main body, the expected effect of preventing the front holder from being inadvertently inserted thereto is lost if the opening of the hood section is too large. For this reason, the opening of the hood section has to be narrower. As a result, the extended hood section is inadequate for a multi-polar connector.
The other measure is to set stronger a holding power with which to temporarily lock the front holder. If, however, the holding power with which to temporarily lock the front holder is set stronger, a stronger force is needed for moving the front holder to the permanent locking position after the terminals are inserted thereto. This deteriorates the workability.